Rotary pump



Jan. 8, 1929. 1,698,235

A. MATHls- ROTARY PUMP File-d Dec. 20, 1924 2 Sheets-Sheet 2 H64 v 555Fla 6 7 'Y v f @Em/waffe MTH/s INVENTOR ATTO EY Patented Jan. 8, 1929.

UNITED 'STATES PATENT OFFICE.

ALEXANDER MATHIS, OF NEW ORLEANS, LOUISIANApASSIGNOR TO MATHIS R-S PUMPCOMPANY, OF DENVER, COLORADO, A CORPORATJON OFYCOL-ORADO.

Romani; PUMP.

Application filed December 2o, 1924; serial no'. 757,182.

The present invention relates to rotary pumps of single or multiplereciprocating piston, or vane, types; said vanes alternately obtrudingand receding during each cycle of 5 the rotor. n

Objects of the invention are to provide a mechanism of simpleconstruction specially adapted to low rotor speeds and capable of'producing a high vacuum, which may be operated by Amanual or mechanicalmeans and which has the elements thereof so organized that the largestpower turn is produced with each revolution of the rotor; to provide acasing of special and novel construction and have rotatably mountedtherein a rotor, also of special and novel construction; to set in orflatten the peripher of a segmental section of this casing and hring itinto substantial contact with "the periphery of the rotor,

abruptly creating and terminating the power chamber and effectivelyseparating the suction from the compression chambers; to provide easyegress of the pistons on the suction stroke and a knife edge scrap-er atthe' inner end of the discharge port or chamber, which will effectivelydeflect all the fluids and any incidental foreign solid matter towardsthe discharge opening; to' so position the ports in the casing as tofacilitate a suction intake with the least possible friction losses dueto the ingress of the finids, and to augment the facility of dischargeof not only the fluids but also and automatically, of all incidentalsolid foreign matter; to provide pistons of special and novelconstruction which, while acting in conjunction with elementshereinafter set forth, reduce frictional resistance to a minimum, yetform an air seal of superior efficiency with .the inner periphery of therotor and the casing on all sides and prevent adherence f yforeignparticles to the casing; to provide a special and suitably design-edcam, or cams,

for automatically, and with the greatest p0s.

sible abruptness, terminating the power cycle of the vanes and relievingthe important sections of the mechanism from all avoidable wear; toprovide a pump which operates with facility and is characterized byA aminimum number of simply constructed parts which are capable ofwithstanding the strain necessarily imposed thereon.

Other objects of the invention will be apparent from the followingdescription of t e present preferred form ofthe invention taken inconnection with the accompanyingl drawings wherein Fig. 1 is a verticalsectional view of a typical pump'constructed in accordance with thisinvention, showing the case, rotor and vanes, the section being takenthrough the ports of 00 the casing but outside of the rotor and vanes;

Fig. 2 is a sectional view of the invention taken approximately alongthe vertical center line 2-2 of Fig. 1;

Fig. 3 is a horizontal sectionalview of the 65 pump showing a portion ofthe rotor broken away to disclose details;

Fig. 4: is an inside elevation view of one of the casing heads showingthe cam formed therein; l

Fig. 5 is a vertical sectional view taken on the line 5 5 of Fig. 4f; l

.Figr is a vertical sectional view of a modified form of casing headshowing the cam formed yseparatel from the head per se;

Fig. 7` is an end elevational view of the rotor; A

Fig. 8 is an elevational view :of the rotor looking at the periphery andshowing a part thereof broken away to disclose details; v 3 Fig. 9 isvan end elevational view of one of the vanes; and

Fig. 10 is a perspective view of the same. j The ldevice of thisinvention consists of a hollow casing 11, of partly circular congurationequipped with an intake port 12, and an exhaust port 13, located at therespective ends of the power chamber. The heads or X ends 14 of thiscasing may be made solid therewith or detachable and bolted thereto asat W 15. Both sides or heads are formed to have bearings 16 and 17concentric with the cyliny' drical part ofthe casing 11, and in axial r.F ment with each other. The casin is s a or flattenedon the 'side ofthe inta'e anc dis- 95 charge ports, as indicated. at 18, and its innerat 21 thereby providing a breast 22 which conintimate contact therewith.

forms to the shape of the rotor 19 and is in This construction willeffectively prevent the compression 'at 13 from reducing the suction at12, thereby increasing the elliciency of performance; At 21 the breastis abruptly terminated in a sharp Wedge preferably slightly diagonal,which, in effect, provides a voluteknife edge scraper in continuoussliding engagement with the eriphery of the rotor, thus, not onlydeilectmg towards the discharge port all the pumpage but alsoeffectively removing from the surface of the rotor all incidentalparticles of foreign matter. Furthermore, lodgement of p articlesbetween the breast 22 and rotor 19 is prevented.

The general configuration of the casing between point and mner periphery23 of the v casing may be either as shown in Fig. 1 or an suitablecombmation of lines, arcs or both, ca

culated'to more or less abruptly bring the periphery 23 of the casing.

vanes into full normal engagement with inner The rotor 19, illustratedin Figs. 7 and'8, 'is made relatively smaller in diameter than theinside diameter of the casing 11, the difference in thesediameters beingcontrolled by considerationsmfdesign of the mechanism as awhole. The'side faces-.24 of the rotor are made to maintain a close slidingcontact with the .inside surfaces of the heads 14V of the casing; Tofurther augment theair sealing features of the rotor `an annular flange25 is provided o-n each side of the rotor which `rform the closestpossible sliding lit on any or all sides within thegrooved recesses 26of l' .basing heads 14.

i 'i Portions 0f the rotor are removed to provide spaces 27' andtherebyreduce the weight of the rotoix 'A shaft 8 is rotatably mounted in thebearings 16 .a Ad 17 ofthe 4casing and may have either one or bothof'itsterminal's extended to permit .the application ofpower thereto.Vane receiving slots-29 are formed in the rotor andare so arranged. thatthe longitudinal axes thereof,` when vertically ar- 29, at theirouterends may openfthrough the ranged asshown'in Fig. l`` will be parallel toa vertical line drawn'through the axis of the rotor. These slots 29 areplaced in communication through openings 32 'which extend through thecenter of t-he rotor. The slots side of both rings 25, or may leavelthese rings intact as shown in Fig. 8. .f v `Each of' he slots 29 has vavane or piston l 33, as shown in Fig. 9,- fitted and reciprocablymounted therein, said vanes being oblong in shape and equipped'withoutstanding wings 35 ontheir advancing faces, the outer ter minals 36conforming to the arc on the inner periphery 23 of the casing 11. Theinner terminals of the vanes are/.equi ped with pins 37 which aremovable into t 1e openings 32 when the vanes are retracted in theirslots.

mounted thereon.- The vanes are normally held apart by helical springs41 which encircle the pins 37 and impinge against the inner ends of thevanes to urge the outer ends of the latter against the yinner periphery23 of casing 11. The springs 41 extend through 'the openings 32 as shownin Fig. 2.

To abruptly terminate compression strokes of the vanes 33, asillustrated by dotted line 42 in Fig. l, the .rollers 40 "are mounted toride on a cam 43. This cam in its entirety, (see Fig. 4) may be formedWithin theA casing heads 14 as illustrated by Fig. 5. If desired,however, the cam and casing head may be made -in two sepa-rate arts, 44and 45 respectively, as illustratedl y Fig. 6. The inner terminal points46 of actuating cams 43 are so located as to vnot only withdraw thevanes along the dotted line 42 of Fig. 1 but also to withdraw the outerterminals of the vanes 36, so as to effectively prevent them fromimpinging on the knife edge 21 of the `casi/ng and destroy its maximumeffectiveness, as set any4 undue Wear on this very important section ofthe casin 4and inevitabll reducing the curvature of tie terminal en s 36of the vanes which would bring about a reduction in their performance,eliiciency and wearing qualities; y

The cam surface over the remaining portionof its magnitude 48 is soshaped as to lpermit unhindered egress of the vanes freni within` therotor on the suction stroke side vand to leave the outer terminals 3d ofthe vanes in full, unrestrained contact with the casing periphery 23,against Vwhich it is VJgently pressed by the springs 41 until the fullpower turn is completed.

In Fig. 1 the arrow to the u per. right hand indicates the direction oft e power turn.

. The lower of the vanes 33 is shown ready to be released from therestraint of the cam surface 47 and ready to goy into position shdwn bythe dotted lines 49. In this position the space from the vane towardsthe port 12 will 4constitute the suction, or vacuum side,- the arcuatedistance of travel from dotted lines 49 to dotted lines 50 constitutingan approximate power turn. When the vane reaches the point indicated bylthe dotted lines 50 it is withdrawn into t e rotor by reason of theconfiguration of the cam upon which the rollers 40 of the vane ride.Point 51 of Fig. 4, representing the beginning of the cam actua-tingsurface, is so positioned. as to cause the vanes to begin to withdrawfrom contact with casing periphery 23 only after the opposite vane,emerging from the rotor on the suction side, has come into engagementwith periphery 23, as illustrated bythe relative positions of 49 and 50of Fig. l.

The position indicated by the dotted lines 52 of Fig. l represents thevane 50 completely withdrawn and ready to pass the breast lor seal 22,the space between the dotted arc of its terminus 36 and the breast 22illustrating the safeguard essential to the proper protection of t-hesurface 22 against undue wear. This latter is very important as theentire efhciency of the mechanism largely depends on/the maintainedcloseness of the sliding l contact between the rotor and this arc 22.

It is apparent that various changes may be made in this deviceespecially in its details of construction, proportlon and arrangement ofparts, within the scope of the appended claims. The device may alsofunction without the specific provisions of the rollers 40, and cams 43,47 and 48 by merely shapingthe casing on the discharge side 13approximately along the dotted line 42 and permitting the outerterminals 36 of the vanes to be actuated thereby on their recedingstrokes.

Therefore the specific formation of the casing and t 1e arrangement ofthe ports, es.

pecially with reference to that part of the casing between the portsmaking a concentric arc contact with the rotor, and the position of thedischarge port with its specific provisions, alone are deemed ofimportance to produce effective results.` Taken in conjunction 'withrotor, vanes and actuating cams as herein set forth, the eciency of theperformance and capacity to resist wear, become very vmateriallyenhanced. These features are therefore considered of para-mountimportance to the production of aneicient, economical and thoroughlydependable device of this kind.

It is also to be understood that although this device is hereindescribed as a rotary pump, it may likewise capaoitate as an engine bythe induction thereinto of Huids under pressure.

-`What is claimed is :-4

l. A rotary pump consisting ofa casing, a breast mounted in the casing,a rotor mounted within the casing in intimate contact with the breast`said casing being provided on one side of said breast with a suctionport and on the other side thereof with a discharge port,

radially opposed vanes slidably mounted within the rotor and equippedwith cam rollers, an inwardly inclined cam formed in each end ofl thecasing the terminals of which are so proportioned along the arc oftravel of the aforesaid cam rollers that the outer ends of the advancingvane will not break contact with the inner periphery of the Casing onthe discharge side of the stroke before the following vane has beenrestored-to contact with the casing periphery and closed the suctionport. l v

2. A. rotary pump consisting of a casing, a rotor equipped with slidablyfitted vanes and cradling breast formed within the casing and inintimate contact with the periphery of the rotor, the terminal edge ofsaid breast on the advancing side of the rotor periphery beingterminated abruptly and formed diagonally with reference to thelongitudinal axis of the rotor, to provide a volute edge scraper incontact with the advancing periphery of said rotor. vf

3. A rotary pump including a casing with a breast formed therein, a camformed in each end of the casing, a rotor revolubl mounted in the casingin contact'with said breast and provided with vane slots, vanes slidablymounted in said slots and equipped with cam engaging rollers, springsurging the vanes from within the rotor on the release side of the camand along the outer terminals of the vanes against the casing during thepower stroke, said springs providing a cushion at the inner limit of thesliding travel of the vanes for absorbing the momentum occa@ sioned bythe withdrawal of the vanesthrough the action of the cam on the camrollers.

4. A rotary pump including a casing p-rovided with inlet and outletports, a rotor revolubly mounted in said casing and equipped with vaneshaving outstanding wings formed thereon for impingement against thecasing, said rotor having slots formed therein which complement andslidably receive said vanes.

5. A rotaryv pump including a casing having a cam formed in each endthereof, a breast formed in the casing, the latter being provide-d withinletand outlet ports, a rotor revolubly mounted in said casing incontact with said breast, and provided with vane slots,

vanes mounted in said slots and equipped with rollers which impinge saidcams for retracting the vanes into the rotor while passing over thecasing breast, and springs interposed between the inner end of each vaneand the bottom of its slot to urge the vane outwardly after the latterpasses over the breast.

ti. A rotary pump including a casing equipped with a breast providedwith an in- `let port on one side of the breast and an outlet port onthe opposite side of the breast, a rotor revolubly mounted/in the casingin 'contact with the breast, means to withdraw the vanes into the rotorwlien passing over the breast, and inde endent means t-o urge the positeside to define acam, a rotor revolubly vanes outwardly aflger the latterhave passed mounted :in `the casing and equipped with 10 over thebreast. rollers projecting into the casing recesses, 7. A rotary pumpincluding a casing proand springs urglng the vanes outwardly to 5 videdwith inlet and outlet ports, the inner yeldingly maintain the'rollersengaged with lface of each end of the casing having a re- 4the wallsofthe recesses.- cess formed therein, the Wall f which is ar- Intestimony whereof I aix my signature. cuate on one side and deformed onthe op- ALEXANDER MATHIS.

